1. Field of the Invention
This invention relates generally to the fields of multimedia and videoconferencing and, more particularly, to displaying a selected area of video having a greater image quality than an unselected area of video.
2. Description of the Related Art
Videoconferencing and/or display of remotely recorded video have achieved broad acceptance in many types of enterprises to facilitate communication between isolated individuals or groups. Also, the local display of locally stored video has become a commonplace capability in modern information processing systems (e.g., personal computer systems, workstations, etc.).
Various types of communication lines are used in videoconferencing to facilitate communication between isolated parties and/or to facilitate the communication of information to and from remote locations. Isolated parties may be remotely located from each other and therefore require communication lines such as regular telephone lines and/or higher speed lines such as asynchronous transfer mode (ATM) transmission lines and Integrated Services Digital Network (ISDN). Alternatively, such isolated parties may be at a local site within which communication may be facilitated through the use of, for example, a communication line of a local area network (LAN).
The quality of displayed video (e.g., in a videoconference) depends largely on the frame rate (e.g., number of frames per second) which is to be maintained. For example, a low frame rate can produce a clear image, whereas image quality decreases if the frame rate increases and the transmission rate remains the same.
The frame rate depends on the information transfer rate of the communication line used in a given application. Many enterprises which use videoconferencing use ISDN lines to transfer information at a rate of 128 Kbps. Products in the consumer market, however, are often designed for the xe2x80x9cPlain Old Telephone Servicexe2x80x9d (POTS) lines which have an information transfer rate at or below 33.6 Kbps. The quality of video transferred at POTS and basic ISDN rates are marginally acceptable in most applications. Such communication lines have a frame rate which varies from one to 10 fps at POTS rates and 5 to 15 fps at ISDN rates. Although the information transfer rate may remain the same, frame rate may vary depending on the amount of information required to be transferred to update an image. For example, the amount of change in an image from one frame to the next frame affects the amount of information transmitted to update the image which in turn causes the frame rate to vary. For example, if there is a lot of motion in the image, frame rate may decrease although the overall information transfer rate remains the same.
Most videoconferencing equipment use video compression technologies to reduce the amount of information to transmit through communication lines. Compression technology in videoconferencing has difficulty maintaining high frame rate and good quality image. One must often be sacrificed in favor of the other. Such is especially true with low bit rates such as basic ISDN and POTS rates.
A video source typically attempts to update the entire video image all the time. However, in many applications in videoconferencing and video on demand, a viewer may only need or desire to look at a particular area of the video image with great detail, at a high frame rate, or both. In videoconferencing applications such as remote diagnosis regarding a patient and remote security monitoring systems, it is often desirable to look at details of a certain area of an image instead of looking at the overall image of the remote site at poor quality.
For example, a doctor who is examining a patient remotely via a videoconferencing system over low bandwidth lines such as basic ISDNI rate lines may want to look at the details of a small area of a patient""s face or hand. The quality of video transmitted from the patient site at basic ISDN rate is marginally acceptable but the frame rate is around 10 frames per second on the average if there is no excessive motion in the image. The doctor must make a diagnosis regarding the patient in a conventional mode in which the entire image from the patient site is updated. As noted, the doctor may want to look at a small area on the face or hand of the patient in detail to closely examine the area. Conventional videoconferencing systems do not provide a way to indicate the small section which the doctor wants to observe, nor can they provide a detailed image of the section.
A similar exemplary situation exists in the context of remote security monitoring systems. Conventionally, the security officer watches an overall image of a remote site such as a remotely observed factory. Occasionally, the security officer may want to examine a suspicious section of the received image in detail if he/she notices something suspicious in the area. Because conventional videoconference systems typically update the entire image at all times, one does not have a choice to observe a small section in the image in detail at higher frame rate.
It has been discovered that a particular area of video may be enhanced in a videoconferencing, video on demand, or similar environment. A methods of digital enhancement and a video region enhancer and system therefore are provided to enhance an area of video smaller than an overall transferred video image in order to provide better quality or greater detail in the relevant area. By specifying an area of video which a system user desires to be viewed, a sender can enhance the image in the specified area by updating the small area at a higher frame rate, improving the resolution of the small area, and/or improving image quality within the area. Information regarding the non-specified area can be reduced and/or sent at a slower rate. Such capability is especially useful in such fields as remote medical diagnoses and remote security systems, for example.
In one embodiment, a digital enhancement method enhances a subsection of video. Video is received by a receiver from a sender. The video includes information for displaying a video image. The subsection of the video for digital enhancement is selected. The selecting the subsection of the video for enhancement includes partitioning the video image into the selected subsection and a remainder unselected subsection. The selected subsection is digitally enhanced by the sender to provide the video including a digitally enhanced subsection. The video including the digitally enhanced subsection is received by the receiver from the sender.
In another embodiment, a system enhances a region of video. The system includes a user interface, a video source, a sending unit and a receiving unit. The sending unit includes a video region enhancer encoder. The video region enhancer encoder is coupled to receive video from the video source. The video includes information for displaying a video image. The video region encoder digitally enhances a selected subsection of the video responsive to the selected subsection being selected by the video region enhancer decoder. The receiving unit includes the video region enhancer decoder. The video region enhancer decoder is coupled to receive video region enhancer window selection notifications from the user interface. The video region enhancer decoder is coupled to receive the video from the video region enhancer encoder. The video region enhancer decoder partitions the video image into a selected subsection and an unselected subsection responsive to receiving a selection notification.
In another embodiment, a method for enhancing a region of video includes selecting a region of video for digital enhancement and digitally enhancing the selected region. The selecting the region of video for enhancement includes defining a selected region of the video and a remainder unselected region of the video such that the video consists of the selected region and the unselected region.
In another embodiment, a method for enhancing a subsection of video includes receiving video by a receiver from a sender. The video including information for displaying a video image. The method further includes selecting the subsection of the video for digital enhancement. The selecting the subsection of the video for enhancement includes partitioning the video image into the selected subsection and a remainder unselected subsection. The method further includes receiving the video by the receiver from the sender after selecting the subsection of the video. The video includes a digitally enhanced subsection corresponding to the selected subsection after selecting the subsection of the video.